"One of the points of contention last year was that the network thinks they have the right to say to the writer of the show, 'We don't want [a character] to do this. We want her to do this', and I would sometimes say back to them that she would never do that," the writer told the New York Observer.

"And they'd look at me like I was crazy, and I'd be like, 'Nope, it's not crazy, it's just who the character is'. You have to respect who the character is. It has its own internal truth and you can't betray that. And if you don't betray that, it will not betray you.

"There is this sort of sense that... if you don't f**k with the muse, the muse will stand by you."

Rebeck went on to reveal that the role of showbiz newcomer Karen - played by Katherine McPhee - was expanded at NBC's request.

"People found her to be a very attractive character, so they asked me to write that," she explained. "I was okay with it. I was like, I've got that in my back pocket.

"The better executives understand that there's supposed to be tension and respect, but a lot of them are just like, 'Do it. You don't own it. Just do it'. That's not a level playing field; you can't have a true discussion."

Smash will return for a revamped second season on February 5, 2013. The series airs on Sky Atlantic in the UK.